Transcranial brain stimulation: potential and limitations

e-Neuroforum ◽  
2014 ◽  
Vol 20 (2) ◽  
Author(s):  
W. Paulus
Keyword(s):  
Electric Fields ◽  
Magnetic Stimulation ◽  
Near Infrared ◽  
Brain Activity ◽  
Electrical Energy ◽  
After Effects ◽  
Network Characteristics ◽  
Neuronal Membranes ◽  
Transcranial Brain Stimulation ◽  
The Brain

AbstractThe brain adapts to new requirements in response to activity, learning or reactions to environmental stimuli by continuous reorgani­zation. These reorganization processes can be facilitated and augmented, or also inhibit­ed and prevented, by transcranial neurostim­ulation. The most common methods are electrical or magnetic stimulation. However, few studies have dealt with the newer methods using near infrared or ultrasound stimulation.Transcranial magnetic stimulation (TMS) allows the pain-free transfer of very short bursts of high intensity electrical energy through the skull and can induce action po­tentials. By varying the number and intensity of the stimuli, and the stimulus sequence, repetitive TMS (rTMS) can induce either inhib­itory or facilitatory effects in the brain. A differentiation is made between short-lived interference with ongoing brain activity, and plastic changes that persist for a longer period beyond the end of the stimulation.Weaker electric fields in the 1 mA range can be applied painlessly through the skull. These probably exert their effects by modulating neuronal membranes and influencing the spontaneous firing rate of cortical neu­rons. They encompass the range from tran­scranial direct current stimulation (tDCS) to high frequency alternating current stimulation (tACS) in the kilohertz range. In view of the multitude of physically possible stimulation algorithms, hypothesis-driven protocols based on cellular or neuronal network characteristics are particularly popular, in the effort to narrow the choices in a meaningful manner. Examples are theta burst stimulation or tACS in the so-called “ripple” frequen­cy range. It is, of course, not possible to selectively stimulate individual neurons using transcranial stimulation techniques; however selective after-effects can be achieved when used in combination with neuropharmacologically active drugs. The use of these methods for neuroenhancement is now a topic of intense discussion.

Digit Force Controls and Corresponding Brain Activities in Finger Pressing Performance: A Comparison Between Older Adults and Young Individuals

2020 ◽  
Vol 28 (1) ◽  
pp. 94-103
Author(s):  
Pai-Yun Cheng ◽  
Hsiao-Feng Chieh ◽  
Chien-Ju Lin ◽  
Hsiu-Yun Hsu ◽  
Jia-Jin J. Chen ◽  
...  
Keyword(s):  
Older Adults ◽  
Infrared Spectroscopy ◽  
Force Control ◽  
Near Infrared ◽  
Brain Activity ◽  
Hand Function ◽  
Young Group ◽  
Primary Motor Area ◽  
Group Response ◽  
The Brain

This study aims toward an investigation and comparison of the digital force control and the brain activities of older adults and young groups during digital pressing tasks. A total of 15 young and 15 older adults were asked to perform force ramp tasks at different force levels with a custom pressing system. Near-infrared spectroscopy was used to collect the brain activities in the prefrontal cortex and primary motor area. The results showed that the force independence and hand function of the older adults were worse than that of the young adults. The cortical activations in the older adults were higher than those in the young group during the tasks. A significant hemodynamic between-group response and mild negative correlations between brain activation and force independence ability were found. Older adults showed poor force independence ability and manual dexterity and required additional brain activity to compensate for the degeneration.

scholarly journals Modelling of the Electric Field Distribution in Deep Transcranial Magnetic Stimulation in the Adolescence, in the Adulthood, and in the Old Age

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Serena Fiocchi ◽  
Michela Longhi ◽  
Paolo Ravazzani ◽  
Yiftach Roth ◽  
Abraham Zangen ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Electric Field ◽  
Electric Fields ◽  
Magnetic Stimulation ◽  
Depressive Disorders ◽  
Brain Structures ◽  
Increasing Demand ◽  
And Gender ◽  
Aging People ◽  
The Brain

In the last few years, deep transcranial magnetic stimulation (dTMS) has been used for the treatment of depressive disorders, which affect a broad category of people, from adolescents to aging people. To facilitate its clinical application, particular shapes of coils, including the so-called Hesed coils, were designed. Given their increasing demand and the lack of studies which accurately characterize their use, this paper aims to provide a picture of the distribution of the induced electric field in four realistic human models of different ages and gender. In detail, the electric field distributions were calculated by using numerical techniques in the brain structures potentially involved in the progression of the disease and were quantified in terms of both amplitude levels and focusing power of the distribution. The results highlight how the chosen Hesed coil (H7 coil) is able to induce the maxima levels ofEmainly in the prefrontal cortex, particularly for the younger model. Moreover, growing levels of induced electric fields with age were found by going in deep in the brain, as well as a major capability to penetrate in the deepest brain structures with an electric field higher than 50%, 70%, and 90% of the peak found in the cortex.

scholarly journals Interpersonal brain synchronization under bluffing in strategic games

2020 ◽  
Vol 15 (12) ◽  
pp. 1326-1335
Author(s):  
Zhihao Wang ◽  
Yiwen Wang ◽  
Xiaolin Zhou ◽  
Rongjun Yu
Keyword(s):  
Near Infrared ◽  
Brain Activity ◽  
Strategic Thinking ◽  
Human Condition ◽  
Angular Gyrus ◽  
Strategic Games ◽  
Functional Near Infrared Spectroscopy ◽  
High Penalty ◽  
The Right ◽  
The Brain

Abstract People commonly use bluffing as a strategy to manipulate other people’s beliefs about them for gain. Although bluffing is an important part of successful strategic thinking, the inter-brain mechanisms underlying bluffing remain unclear. Here, we employed a functional near-infrared spectroscopy hyperscanning technique to simultaneously record the brain activity in the right temporal-parietal junction in 32 pairs of participants when they played a bluffing game against each other or with computer opponents separately. We also manipulated the penalty for bluffing (high vs low). Under the condition of high relative to low penalty, results showed a higher bluffing rate and a higher calling rate in human-to-human as compared to human-to-computer pairing. At the neural level, high relative to low penalty condition increased the interpersonal brain synchronization (IBS) in the right angular gyrus (rAG) during human-to-human as compared to human-to-computer interaction. Importantly, bluffing relative to non-bluffing, under the high penalty and human-to-human condition, resulted in an increase in response time and enhanced IBS in the rAG. Participants who bluffed more frequently also elicited stronger IBS. Our findings support the view that regions associated with mentalizing become synchronized during bluffing games, especially under the high penalty and human-to-human condition.

scholarly journals Transcranial magnetic stimulation: studying the brain--behaviour relationship by induction of ‘virtual lesions’

1999 ◽  
Vol 354 (1387) ◽  
pp. 1229-1238 ◽  
Author(s):  
Alvaro Pascual-Leone
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Brain Connectivity ◽  
Brain Activity ◽  
Causal Link ◽  
Non Invasive ◽  
Invasive Method ◽  
Normal Humans ◽  
The Brain ◽  
Neuroimaging Techniques

Transcranial magnetic stimulation (TMS) provides a non-invasive method of induction of a focal current in the brain and transient modulation of the function of the targeted cortex. Despite limited understanding about focality and mechanisms of action, TMS provides a unique opportunity of studying brain-behaviour relations in normal humans. TMS can enhance the results of other neuroimaging techniques by establishing the causal link between brain activity and task performance, and by exploring functional brain connectivity.

scholarly journals Shining Light On The Brain to Understand How It Works

2021 ◽  
Vol 9 ◽  
Author(s):  
Laura Bell ◽  
Vanessa Reindl ◽  
Jana A. Kruppa ◽  
Alexandra Niephaus ◽  
Simon H. Kohl ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared ◽  
Brain Activity ◽  
Infrared Light ◽  
Functional Near Infrared Spectroscopy ◽  
Near Infrared Light ◽  
Daily Lives ◽  
Long Run ◽  
Total Light ◽  
The Brain

Have you ever thought that light could tell you something about your brain? Light is a powerful tool that helps brain researchers understand the brain. Our eyes can only see <1% of the total light around us. Some of the light is red, so-called near-infrared light. This type of light can travel through the head and the top layers of the brain, and thereby gives researchers important information about brain activity. The technique that uses near-infrared light has a long name: functional near-infrared spectroscopy (fNIRS). In this article, we will show you what a fNIRS machine looks like and what it is like to take part in a fNIRS experiment. We will explain how we can use near-infrared light to better understand the brain. Finally, we will give you some examples of what we use fNIRS for and how it might help children who face difficulties in their daily lives in the long run.

scholarly journals Electric field dependent effects of motor cortical TDCS

2018 ◽  
Author(s):  
Ilkka Laakso ◽  
Marko Mikkonen ◽  
Soichiro Koyama ◽  
Daisuke Ito ◽  
Tomofumi Yamaguchi ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Primary Motor Cortex ◽  
Cortical Excitability ◽  
Brain Anatomy ◽  
After Effects ◽  
Neuropsychiatric Diseases ◽  
Motor Cortical ◽  
The Individual ◽  
The Brain

AbstractTranscranial direct current stimulation (TDCS) can modulate motor cortical excitability. However, its after-effects are highly variable between individuals. Individual cranial and brain anatomy may contribute to this variability by producing varying electric fields in each subject’s brain. Here we show that these fields are related to excitability changes following anodal TDCS of the primary motor cortex (M1). We found in two experiments (N=28 and N=9) that the after-effects of TDCS were proportional to the individual electric field in M1, calculated using MRI-based models. Individuals with the lowest and highest local electric fields in M1 tended to produce opposite changes in excitability. Furthermore, the effect was field-direction dependent and non-linear with stimulation duration or other experimental parameters. The electric field component pointing into the brain was negatively proportional to the excitability changes following 1 mA 20 min TDCS of right M1 (N=28); the effect was opposite after 1 mA 10 min TDCS of left M1 (N=9). Our results demonstrate that a large part of variability in the after-effects of motor cortical TDCS is due to inter-individual differences in the electric fields. We anticipate that individualized electric field dosimetry could be used to control the neuroplastic effects of TDCS, which is increasingly being explored as a treatment for various neuropsychiatric diseases.

scholarly journals SimNIBS 2.1: A Comprehensive Pipeline for Individualized Electric Field Modelling for Transcranial Brain Stimulation

2018 ◽  
Author(s):  
Guilherme B. Saturnino ◽  
Oula Puonti ◽  
Jesper D Nielsen ◽  
Daria Antonenko ◽  
Kristoffer Hougaard H Madsen ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Brain Stimulation ◽  
Head Model ◽  
Non Invasive ◽  
Field Modelling ◽  
Transcranial Brain Stimulation ◽  
Automated Tools ◽  
Automated Placement ◽  
The Brain

Numerical simulation of the electric fields induced by Non-Invasive Brain Stimulation (NIBS), using realistic anatomical head models has gained interest in recent years for understanding the NIBS effects in individual subjects. Although automated tools for generating the head models and performing the electric field simulations have become available, individualized modelling is still not standard practice in NIBS studies. This is likely partly explained by the lack of robustness and usability of the previously available software tools, and partly by the still developing understanding of the link between physiological effects and electric field distributions in the brain. To facilitate individualized modelling in NIBS, we have introduced the SimNIBS (Simulation of NIBS) software package, providing easy-to-use automated tools for electric field modelling. In this article, we give an overview of the modelling pipeline in SimNIBS 2.1, with step-by-step examples of how to run a simulation. Furthermore, we demonstrate a set of scripts for extracting average electric fields for a group of subjects, and finally demonstrate the accuracy of automated placement of standard electrode montages on the head model. SimNIBS 2.1 is freely available at www.simnibs.org.

Basic Study on the Effect of Scent on Arousal Level Using Multi-Channel Near-Infrared Spectroscopy (MNIRS)

2011 ◽  
pp. 172-182
Author(s):  
Shun’ichi Doi ◽  
Takahiro Wada ◽  
Eiji Kobayashi ◽  
Masayuki Karaki ◽  
Nozomu Mori
Keyword(s):  
Near Infrared ◽  
Brain Activity ◽  
Functional Brain Imaging ◽  
Arousal Level ◽  
Brain Blood Flow ◽  
Basic Study ◽  
Individual Subject ◽  
Functional Brain ◽  
The Individual ◽  
The Brain

As a result, it is verified that not only characteristics of the scent but also the driver’s preference and subjective judgment of scent changes affect on the each driving performance. The brain activity change by olfactory stimulation and the brain blood flow change by other stimulation were also investigated. The effects of the functional brain imaging of olfactory activity were measured and the comfortable scent for the individual subject was verified to be effective for maintaining the arousal level.

scholarly journals Caffeine Effect on Cognitive Function during a Stroop Task: fNIRS Study

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yafei Yuan ◽  
Guanghao Li ◽  
Haoran Ren ◽  
Wei Chen
Keyword(s):  
Cognitive Function ◽  
Task Performance ◽  
Stroop Task ◽  
Near Infrared ◽  
Brain Activity ◽  
Brain Activation ◽  
Infrared Light ◽  
Functional Near Infrared Spectroscopy ◽  
Feedback Information ◽  
The Brain

Acting as a brain stimulant, coffee resulted in heightening alertness, keeping arousal, improving executive speed, maintaining vigilance, and promoting memory, which are associated with attention, mood, and cognitive function. Functional near-infrared spectroscopy (fNIRS) is a noninvasive optical method to monitor brain activity by measuring the absorption of the near-infrared light through the intact skull. This study is aimed at acquiring brain activation during executing task performance. The aim is to explore the effect of coffee on cognitive function by the fNIRS neuroimaging method, particularly on the prefrontal cortex regions. The behavioral experimental results on 31 healthy subjects with a Stroop task indicate that coffee can easily and effectively modulate the execute task performance by feedback information of the response time and accuracy rate. The findings of fNIRS showed that apparent hemodynamic changes were detected in the bilateral VLPFC regions and the brain activation regions varied with different coffee conditions.

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